Depends on what you want.
Keep in mind that there is cute little place at the border called "at the border storage" and if you can find a set of tire on ebay that offer free shipping in the states, you ship it to these guys, you pay them a very small amount, bring them across the border yourself and save on brokerage, however you have to make the trip down there.
I think they are at the sweetgrass/coutts border.
I just put a set of tires on a company truck at fountain tire, 285/70/18 goodyear duratracs. I had them studded, installed, balanced, paid tax and it was <1400 out the door. I thought that was pretty good for a pretty uncommon tire size (but I didnt care because I did pay for them either).